Braid

Does anyone know exactly what the famous indie game Braid was coded in? From what I can tell it was some C++ compatible libraries. I'm curious as it looked good though I doubt one person would have the time to write all this in Directx or Opengl, though the author gave the limitations of XNA as it wasn't that.

The language it was coded in was almost certainly C and/or C++.

The original developer, Jonathan Blow, developed the game for Xbox 360's Xbox LIVE Arcade and Windows. As far as I know, he did all the design and coding himself, but outsourced the content (audio/graphics), and it took him about three years. For these platforms he would have used DirectX 9 and the Xbox 360's own graphics libraries that are built on DirectX (they are almost identical to DirectX 9.0c) along with some other platform-specific libraries. I imagine he probably used DirectInput/XInput and XAudio2 for input and audio respectively, but I can't say for certain.

The game was ported to other platforms (Mac OSX, PSN, and Linux), but apparently not by Jonathan Blow (according to Wikipedia it was done by a development studio called Hothead Games - Braid (video game) - Wikipedia). For these platforms they will have used OpenGL for graphics (I believe the PS3's graphics libraries are built on OpenGL), along with platform specific APIs for other things such as audio, filesystems and input.

C#/XNA does have some limitations compared to C++/DirectX, but I reckon a game like Braid would be well within the capabilities of XNA. It's all swings and roundabouts anyway.

Blow confirms in his development blog that Braid was originally written in C++, using Visual Studio.
He also claims here that

Braid would simply not work in any language slower than C++; I had to do a lot of optimization to even get it to run at reasonable speeds on the xbox.

Take that quote for what it's worth; though I suppose, as Ushakal said, Braid would be fine in C# on a modern PC.

Braid would be fine in C# on a modern PC.

Having played it and experienced it's very cool time feature I seriously doubt any other language could pull this off and still be playable.